9.25 * 10^21 pennies if how many moles

there are 25 elements found in living things. how many of these elements are found in some organisms but not at all?

2. 10 kg of food at a moisture content of 320% dry basis is dried to 50% wet basis. Calculate the amount of water removed

Ionizing radiation causes cancer by Select one: a. forming ions, causing reactions that mutate DNA b. forming ions, causing reactions that mutate bacteria c. forming ions, causing reactions that form products that cancer cells eat d.

Use the data table to answer the questions below Mass of evaporating dish ... 12.07g Mass of evaporating dish plus hydrate ... 15.12 g Mass of evaporating dish and anhydrous crystals ... 13.

Which of the following statements is true? Ca does not react with other atoms because it has 8 electrons in its outermost shell. Mg does not react with other atoms because its outermost shell is complete.

Iodine-131 decays to form xenon-131. the half-life of this reaction is 8.07 days. from a 200-g sample of iodine-131, how much of the sample is xenon-131 after 16.14 days?

Complete the following statement by checking all that apply Creativity allows scientists to develop multiple approaches to solving problems. adapt to changes in scientific knowledge. look at old problems in new ways.

The atomic weight of hydrogen is 1.00794. a. True b. False

Describe What kind of ions do metals form? What kind of ions do nonmetals form?

A car is driven through streets treated with salt and then parked in a warm garage. a) How will the rate of rusting compare with a car that has not been driven in the streets treated with salt but left parked outside?